The present invention relates to computer modeling and simulation of moving bodies, more particularly to computer modeling and simulation representative of dynamic trajectories of guided, self-propelled devices such as homing missiles and some air vehicles.
Currently, the highest-fidelity simulations of the trajectories of moving bodies are produced by so-called “six-degrees-of-freedom” (“6DOF”) models. These conventional modeling methods take into account as much physics and engineering data as possible about the forces acting on the body, and produce detailed, accurate trajectories. In particular, 6DOF models are dynamic in the sense that they can show with great detail how a body whose motion is designed to maneuver toward an aimpoint can alter its trajectory if the aimpoint changes (or how plural bodies whose respective motions are designed to maneuver toward respective aimpoints can alter their respective trajectories if the respective aimpoints change).
However, 6DOF methods require intensive computational effort, and therefore usually consume a lot of time. For simulations with many simultaneously moving bodies, 6DOF models may take too long to compute trajectories (typically minutes for a single body), thus violating an application's overall simulation run-time requirements (which may require, for instance, hundreds of trajectories to be computed in less than a minute).
Greatly simplified trajectory models have been disclosed in the literature that may be produced using a paradigm in which the body trajectory (as determined by a high-fidelity 6DOF simulation) is separated into (ii) the overall trajectory shape, and (ii) the speed along the shape as a function of time. The present inventor has coined the term “bead-on-a-wire” in referring to this paradigm in general. Using the present inventor's terminology, according to the “bead-on-a-wire”paradigm, the body trajectory is separated into (i) the “wire” (overall trajectory shape), and (ii) the speed along the “wire” as a function of time.
Bead-on-a-wire models have the potential to be computed orders of magnitude faster than 6DOF models. However, these simplified models, as they are currently known, are not truly dynamic; that is, they cannot show how the trajectory changes dynamically with a moving aimpoint except in the simplest cases, where the body always moves along the straight line connecting the body to the current aimpoint.
Of interest herein, incorporated herein by reference, is Patricia A. Hawley and Ross A. Blauwkamp, “Six-Degree-of-Freedom Digital Simulations for Missile Guidance, Navigation, and Control,” Johns Hopkins Applied Physics Laboratory (APL) Technical Digest, Laurel, Md., Volume 29, Number 1, pages 71-84, 2010.
Also of interest herein, incorporated herein by reference, is James J. Little and Zhe Gu, “Video Retrieval by Spatial and Temporal Structure of Trajectories,” Proceedings of the SPIE, Volume 4315, pages 545-552, Storage and Retrieval for Media Databases, International Society for Optics and Photonics, 2001.